Sex-related differences in exercise performance and outcome of patients with hypertrophic cardiomyopathy

Cardiomyopathies in Women

Heart failure affects over 2.6 million people in the United States. While women have better overall survival rates, they also suffer from higher morbidity as shown by higher rates of hospitalization and worse quality of life. Several anatomical differences in women's hearts affect both systolic and diastolic cardiac physiology. Despite these findings, women are significantly underrepresented in clinical trials, necessitating extrapolation of data from males. Because women have sex-specific etiologies of heart failure and unique manifestations in genetic-related cardiomyopathies, meaningful sex-related differences affect heart failure outcomes as well as access to and outcomes in advanced heart failure therapies in women. This review explores these gender-specific differences and potential solutions to balance care between women and men.

A systematic review and meta-analysis of sex differences in clinical outcomes of hypertrophic cardiomyopathy

Background

Hypertrophic cardiomyopathy (HCM) is recognized as the most prevalent form of genetic cardiomyopathy, and recent investigations have shed light on the existence of sex disparities in terms of clinical presentation, disease progression, and outcomes.

Objectives

This study aimed to systematically review the literature and perform a meta-analysis to comprehensively compare the clinical outcomes between female and male patients with HCM.

Methods

A thorough search was conducted in databases including PubMed, Embase, Cochrane Library, and Web of Science, encompassing literature from inception until June 2023. The primary endpoints examined were: (1) all-cause mortality; (2) an arrhythmic endpoint comprising sudden cardiac death (SCD), sustained ventricular tachycardia, ventricular fibrillation, or aborted SCD; and (3) a composite endpoint incorporating either (1) or (2), in addition to hospitalization for heart failure or cardiac transplantation. Pooled estimates were derived using a random-effects meta-analysis model.

Results

The analysis encompassed a total of 29 observational studies, involving 44,677 patients diagnosed with HCM, of which 16,807 were female. Baseline characteristics revealed that the female group exhibited an advanced age [55.66 ± 0.04 years vs. 50.38 ± 0.03 years, pooled mean difference (MD) = 0.31, 95% CI: 0.22-0.40, p = 0.000, I2 = 88.89%], a higher proportion of New York Heart Association class III/IV patients [pooled odds ratio (OR) = 1.94, 95% CI: 1.55-2.43, p = 0.000, I2 = 85.92%], and a greater prevalence of left ventricular outflow tract gradient greater than or equal to 30 mmHg (pooled OR = 1.48, 95% CI: 1.27-1.73, p = 0.000, I2 = 68.88%) compared to the male group. The female group were more likely to have a positive genetic test (pooled OR = 1.27, 95% CI: 1.08-1.48, p = 0.000, I2 = 42.74%) and to carry the myosin heavy chain beta 7 mutation (pooled OR = 1.26, 95% CI: 1.04-1.54, p = 0.020, I2 = 0.00%) compared to the male group. Female sex exhibited a significant association with increased risks of all-cause mortality (pooled OR = 1.62, 95% CI: 1.38-1.89, p = 0.000, I2 = 72.78%) and the composite endpoint (pooled OR = 1.47, 95% CI: 1.20-1.79, p = 0.000, I2 = 84.96%), while no substantial difference was observed in the arrhythmic endpoint (pooled OR = 1.08, 95% CI: 0.87-1.34, p = 0.490, I2 = 55.48%).

Conclusions

The present findings suggest that female patients with HCM tend to experience poorer clinical outcomes. It is imperative to critically reevaluate disease definitions and enhance awareness to mitigate delays in the diagnosis and treatment of HCM in women, thereby fostering equitable healthcare practices.

Systematic Review Registration

https://www.crd.york.ac.uk/, PROSPERO (CRD42023431881).

Sex Differences in Heart Failure: What Do We Know?

Heart failure (HF) remains an important global health issue, substantially contributing to morbidity and mortality. According to epidemiological studies, men and women face nearly equivalent lifetime risks for HF. However, their experiences diverge significantly when it comes to HF subtypes: men tend to develop HF with reduced ejection fraction more frequently, whereas women are predominantly affected by HF with preserved ejection fraction. This divergence underlines the presence of numerous sex-based disparities across various facets of HF, encompassing aspects such as risk factors, clinical presentation, underlying pathophysiology, and response to therapy. Despite these apparent discrepancies, our understanding of them is far from complete, with key knowledge gaps still existing. Current guidelines from various professional societies acknowledge the existence of sex-based differences in HF management, yet they are lacking in providing explicit, actionable recommendations tailored to these differences. In this comprehensive review, we delve deeper into these sex-specific differences within the context of HF, critically examining associated definitions, risk factors, and therapeutic strategies. We provide a specific emphasis on aspects exclusive to women, such as the impact of pregnancy-induced hypertension and premature menopause, as these unique factors warrant greater attention in the broader HF discussion. Additionally, we aim to clarify ongoing controversies and knowledge gaps pertaining to the pharmacological treatment of HF and the sex-specific indications for cardiac implantable electronic devices. By shining a light on these issues, we hope to stimulate a more nuanced understanding and promote the development of more sex-responsive approaches in HF management.

Factors associated with excess female mortality in obstructive hypertrophic cardiomyopathy

BACKGROUND

Several studies have reported excess female mortality in patients with hypertrophic cardiomyopathy, but the cause is unknown.

AIMS

To compare risk-factors for disease-related death in both sexes in a geographical cohort of patients with obstructive hypertrophic cardiomyopathy (oHCM).

METHODS AND RESULTS

Data-bases in all ten hospitals within West Götaland Region yielded 250 oHCM-patients (123 females, 127 males). Mean follow-up was 18.1 y. Risk-factors for disease-related death were evaluated by Cox-hazard regression and Kaplan-Meier survival-curves, with sex-comparisons of distribution of risk-factors and therapy in total and age-matched (n = 166) groups. At diagnosis females were older, median 62 y vs. 51 y, (P < 0.001), but not different in outflow-gradients and median NYHA-class. However, septal hypertrophy was more advanced: 10.6 [IQR = 3.2] vs. 9.6 [2.5] mm/m2 BSA; P = 0.002. Females had higher disease-related mortality than males (P = <0.001), with annual mortality 2.9% vs. 1.5% in age-matched groups (P = 0.010 log-rank). For each risk-category identified (NYHA-class ≥ III, outflow-gradient ≥50 mmHg), a higher proportion of females died (P = 0.0004; P = 0.001). Calcium-blocker therapy was a risk-factor (P = 0.005) and was used more frequently in females (P = 0.034). A beta-blocker dose above cohort-median reduced risk for disease-related death in both males (HR = 0.32; P = 0.0040) and in females (HR = 0.49; P = 0.020). Excess female deaths occurred in chronic heart-failure (P = 0.001) and acute myocardial infarctions (P = 0.015). Fewer females received beta-blocker therapy after diagnosis (64% vs. 78%, P = 0.018), in a smaller dose (P = 0.007), and less frequently combined with disopyramide (7% vs. 16%, P = 0.048).

CONCLUSION

Addressing sex-disparities in the timing of diagnosis and pharmacological therapy has the potential to improve the care of females with oHCM.

Gender disparities in alcohol septal ablation for hypertrophic obstructive cardiomyopathy

OBJECTIVE

Alcohol septal ablation (ASA) improves symptoms in hypertrophic obstructive cardiomyopathy (HOCM). We conducted a large retrospective analysis investigating gender effects on outcome after ASA.

METHODS AND RESULTS

1367 ASAs between 2002 and 2020 were analysed. Women (47.2%) were older (66.0 years (IQR 55.0-74.0) vs 54.0 years (IQR 45.0-62.0); p<0.0001) with more severe symptoms. The interventricular septal diameter (IVSD) was higher in men (21.0 mm (IQR 19.0-24.0) vs 20.0 mm (IQR 18.0-23.0); p<0.0001) but the IVSD indexed to body surface area was higher in women (10.9 mm/m² (IQR 9.7-12.7) vs 10.2 mm/m² (IQR 9.0-11.7); p<0.0001). Women had lower exercise-induced left ventricular outflow tract gradients (LVOTG) 1-4 days after ASA (55.0 mm Hg (IQR 30.0-109.0) vs 71.0 mm Hg (IQR 37.0-115.0); p=0.0006). There was a trend for lower resting LVOTG 1-4 days after ASA (20.0 mm Hg (IQR 12.0-37.5) vs 22.0 mm Hg (IQR 13.0-40.0); p=0.0062) and lower exercise-induced LVOTG after 6 months in women (34.0 mm Hg (IQR 21.0-70.0) vs 43.5 mm Hg (IQR 25.0-74.8); p=0.0072), but this was not statistically significant after Bonferroni correction. More women developed atrioventricular (AV) block (20.3% vs 13.3%; p=0.0005) and required a pacemaker (17.4% vs 10.4%; p=0.0002) but not a cardioverter defibrillator (9.0% vs 11.6% in men; p=n .s.). However, in multivariable regression models, there was no evidence that sex independently influenced LVOTG and the occurrence of AV block.

CONCLUSION

Female patients with HOCM were older and had more advanced disease at the time of ASA. Women had superior short-term haemodynamic response to ASA but more often developed AV block after ASA. These results are important to consider for sex-specific counselling before ASA.

Sex-Related Differences in Genetic Cardiomyopathies

Cardiomyopathies are a heterogeneous collection of diseases that have in common primary functional and structural abnormalities of the heart muscle, often genetically determined. The most effective categorization of cardiomyopathies is based on the presenting phenotype, with hypertrophic, dilated, arrhythmogenic, and restrictive cardiomyopathy as the prototypes. Sex modulates the prevalence, morpho-functional manifestations and clinical course of cardiomyopathies. Aspects as diverse as ion channel expression and left ventricular remodeling differ in male and female patients with myocardial disease, although the reasons for this are poorly understood. Moreover, clinical differences may also result from complex societal/environmental discrepancies between sexes that may disadvantage women. This review provides a state-of-the-art appraisal of the influence of sex on cardiomyopathies, highlighting the many gaps in knowledge and open research questions.

Age-related sex differences in the outcomes of patients with hypertrophic cardiomyopathy

BACKGROUND

We aimed to clarify the sex differences in various cardiovascular and non-cardiovascular outcomes, and to investigate whether sex differences in outcomes are affected by age in hypertrophic cardiomyopathy (HCM).

METHODS

A cohort of 835 patients with HCM initially evaluated during 2007-2019 were followed for a median of 6.4 years. Study outcomes were all-cause death, cardiovascular and non-cardiovascular death, sudden cardiac death (SCD)/SCD equivalent events, heart failure (HF) events, and the composite cardiovascular outcome including cardiovascular death, SCD/SCD equivalent events, admission for HF, and heart transplantation.

RESULTS

Women were 5 years older (women 59.9±13.5 vs. men 54.9±11.4 years), had worse dyspnea, and greater left ventricular (LV) diastolic dysfunction and obstructive physiology at presentation. Women compared to men had higher all-cause mortality and cardiovascular event rates, driven by more cardiovascular deaths and heart failure (HF) events. Conversely, non-cardiovascular mortality was not different between the sexes. Female sex was independently associated with all-cause death (HR 1.88, 95% CI 1.11-3.20) and composite cardiovascular events (HR 3.60, 95% CI 2.00-6.49), independent of age, body mass index, New York Heart Association class, SCD risk score, and LV ejection fraction. When stratified by the age of 60, sex differences were not significant at <60 years; however, at ≥60 years, women had worse LV diastolic function, greater obstructive physiology, as well as worse survival and composite cardiovascular outcomes. Sex differences in outcomes remained consistent after propensity score matching for age and other clinical characteristics.

CONCLUSIONS

Women with HCM have worse cardiovascular prognosis than men, driven by higher cardiovascular mortality and HF events. The negative impact of female sex on cardiac function and cardiovascular outcome became prominent at age ≥60 years, suggesting age-related sex differences in the prognosis of HCM.

Gender-Related Differences in Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis

Background

Gender-related differences in phenotypic expression and outcomes have been established in many cardiac conditions; however, the impact of gender in hypertrophic cardiomyopathy (HCM) remains unclear. We conducted a systematic review and meta-analysis to assess the differences in clinical outcomes between female and male HCM patients.

Methods

We searched MEDLINE and EMBASE from inception to October 2020. Included were cohort studies that compared outcomes of interest including all-cause mortality, HCM-related mortality, and worsening heart failure (HF) or HF hospitalization between male and female. Data from each study were combined using the random effects model to calculate pooled odds ratio (OR) with 95% confidence interval (CI).

Results

Eleven retrospective cohort studies with a total of 9,427 patients (3,719 females) were included. Female gender was significantly associated with an increased risk of all-cause mortality (pooled OR = 1.63, 95% CI: 1.26-2.10, p ≤ 0.001), HCM-related mortality (pooled OR = 1.47, 95% CI: 1.08-2.01, p = 0.015), and worsening HF or HF hospitalization (pooled OR = 2.05, 95% CI: 1.76-2.39, p ≤ 0.001).

Conclusions

Female gender was associated with a worse prognosis in HCM. These findings suggest the need for improved care in women including early identification of disease and more possible aggressive management. Moreover, gender-based strategy may benefit in HCM patients.

Cardiopulmonary Exercise Test in Patients with Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with chronic diseases frequently adapt their lifestyles to their functional limitations. Functional capacity in Hypertrophic Cardiomyopathy (HCM) can be assessed by stress testing. We aim to review and analyze the available data from the literature on the value of Cardiopulmonary Exercise Test (CPET) in HCM. Objective measurements from CPET are used for evaluation of patient response to traditional and new developing therapeutic measurements.

METHODS

A systematic review of the literature was conducted in PubMed, Web of Science and Cochrane in Mar-20. The original search yielded 2628 results. One hundred and two full texts were read after the first screening, of which, 69 were included for qualitative synthesis. Relevant variables to be included in the review were set and 17 were selected, including comorbidities, body mass index (BMI), cardiac-related symptoms, echocardiographic variables, medications and outcomes.

RESULTS

Study sample consisted of 69 research articles, including 11,672 patients (48 ± 14 years old, 65.9%/34.1% men/women). Treadmill was the most common instrument employed (n = 37 studies), followed by upright cycle-ergometer (n = 16 studies). Mean maximal oxygen consumption (VO2max) was 22.3 ± 3.8 mL·kg^-1·min^-1. The highest average values were observed in supine and upright cycle-ergometer (25.3 ± 6.5 and 24.8 ± 9.1 mL·kg^-1·min^-1; respectively). Oxygen consumption in the anaerobic threshold (ATVO2) was reported in 18 publications. Left ventricular outflow tract gradient (LVOT) > 30 mmHg was present at baseline in 31.4% of cases. It increased to 49% during exercise. Proportion of abnormal blood pressure response (ABPRE) was higher in severe (>20 mm) vs. mild hypertrophy groups (17.9% vs. 13.6%, p < 0.001). Mean VO2max was not significantly different between severe vs. milder hypertrophy, or for obstructive vs. non-obstructive groups. Occurrence of arrhythmias during functional assessment was higher among younger adults (5.42% vs. 1.69% in older adults, p < 0.001). Twenty-three publications (9145 patients) evaluated the prognostic value of exercise capacity. There were 8.5% total deaths, 6.7% cardiovascular deaths, 3.0% sudden cardiac deaths (SCD), 1.2% heart failure death, 0.6% resuscitated cardiac arrests, 1.1% transplants, 2.6% implantable cardioverter defibrillator (ICD) therapies and 1.2 strokes (mean follow-up: 3.81 ± 2.77 years). VO2max, ATVO2, METs, % of age-gender predicted VO2max, % of age-gender predicted METs, ABPRE and ventricular arrhythmias were significantly associated with major outcomes individually. Mean VO2max was reduced in patients who reached the combined cardiovascular death outcome compared to those who survived (-6.20 mL·kg^-1·min^-1; CI 95%: -7.95, -4.46; p < 0.01).

CONCLUSIONS

CPET is a valuable tool and can safely perform for assessment of physical functional capacity in patients with HCM. VO2max is the most common performance measurement evaluated in functional studies, showing higher values in those based on cycle-ergometer compared to treadmill. Subgroup analysis shows that exercise intolerance seems to be more related to age, medication and comorbidities than HCM phenotype itself. Lower VO2max is consistently seen in HCM patients at major cardiovascular risk.